Year Percent change (Units) 2001 16.348 2002 -6.701 2003 -2.182 2004 0.400 2005 2.988 2006 -4.119 2007 10.262 2008 11.391 2009 10.144 2010 9.329 2011 5.956 2012 4.853 2013 3.068 2014 4.512 2015 2.761 2016 3.385 2017 -3.058 2018 -0.690 2019 2.075 2020 -7.241 2021 1.597 2022 3.994 2023 1.500 2024 3.500 2025 3.200 2026 3.100 2027 3.000 2028 3.000 2029 3.000